SU1288579A1 - Method and apparatus for multiparameter electromagnetic checking of ferromagnetic articles - Google Patents

Abstract

The invention relates to methods for non-destructive testing of physical and technical indicators of ferromagnetic products and can be used in industry to determine the strength characteristics of the products being tested. The aim of the invention is to increase the accuracy of control due to the introduction of an additional mode of magnetization by a triangular-shaped current. The product is affected by an electromagnetic field, the intensity of which varies according to the system of functions of the Tauder when the frequencies of the exciting current change. In this case, additional corrections of the magnetizing current are introduced to adjust the noticing factors. The determination of the correction parameters is made by preliminary training sample on the reference products. The device implementing this method contains a mini-computer that controls the operation of the magnetizing current and test bench controllers via the interface. The controlled part is magnetized in the electromagnetic transducer simultaneously with the reference, undergoes elastic deformation, the value of which is recorded by the strain gauges, and through the analog switch the information signals are fed into the analog-to-digital converter and digitally at the interface input. By adaptively changing the effect parameters, training is carried out to control the appropriate type of products. 2 sec. f-ly, 1 ill. sl 1chO 00 ate with

Description

I

-12885

This invention relates to methods of destructive control of the physicomechanical parameters of ferromagnetic objects and can be used in. engineering industry for structural analysis.

The purpose of the invention is to improve the accuracy of control of the parameters of products by introducing an additional triangular-shaped magnetization mode.

The drawing shows the block diagram of the device that implements the proposed method.

The device contains a magnetizing unit 1 connected in series and two electromagnetic transducers 2 and 3 two strain gauge converters 4 and 5, a selector 6 connected in series 6 a control commutator unit 7 analog switch 8, to the inputs of which electromagnetic converters 2 and 3 and strain gauges 4 and 4 are connected 5., analog-to-digital converter 9 and the block IO of the buffer memory.

The device also contains an interface node 115 consisting of a serially connected address decoder 12, an acknowledgment control unit 13, a transceiver unit 14 whose inputs are connected to a selector 6 and a buffer memory unit 10, and input and output registers 15 and 16 .. The interface node 11 also contains serially connected control register 7 and bus driver 18, the output of which is connected to memory selector 6 and memory decoder 12, the device also connected in series control a stand 19 connected to the selector 6, and an executive mechanism 20, connected in series by a magnetizing current controller 21, a multiplexer 22, two registers 23 and 24, a control generator 25 and a magnetizing current driver 26 associated with input and output registers 15 and 16 and control register 17.

The method is implemented in the following way.

The controlled object is affected by an electromagnetic field varying in a triangular shape (according to

five

79 2 Schauder function system) in a wide frequency range (10 Hz -100 kHz) sounding. The initial amplitude values of the latter at the corresponding analysis frequencies are set such5 that the level of the higher Walsh harmonics in the spectrum of the signal of the primary measuring generator at all selected analysis frequencies is constant (for example, 0.5%), and the amplitude of the sounding is additionally corrected to compensate for the contribution due to structure variation, numerically equal in magnitude K A, where

Tj

0

five

0

0

0

Ke - (/ (a, where, 61, ff

) Cha, - | -) H (a, | -H

69

according to the assessment of hardness, yield strength, limit of prog-. values determined in the first magnetization mode; , p 5 6, 6g - indicated strength characteristics of the reference (reference) part; a,, a, j 5 a are the weighting factors determined in a cycle, training on a representative training sample of witness samples according to the criterion of the minimum variance of an error;

And - the initial amplitude of the signal at the frequency of analysis

To eliminate the influence of the interfering factor due to the significant transformation of the rheological function of the object of control in the Ti4, the phase rheological transition of the first and second types is performed | e | (e) | , according to the proposed method, an additional correction of the amplitude of sounding is carried out, proportional to K, A, where

./ch :(.)

4 b, (.6

e-g

l ;,

and g ,, t

 bj

2

-)

weighting factors (constant for a given type of product), which are set in the training cycle on a representative sample; (Y is the value corresponding to the limiting transition to the region of the first type rheological transition.

Subsequently, reference (interchangeable) samples of the first group are influenced by the initial amplitudes at the analysis frequencies and the spectral composition (in the Walsh basis) of the response of the electrodynamic converter is recorded, while loading the reference samples in the Hooke region and installed in the electrodynamic conversion bodies use Walsh spectral components recorded at local analysis intervals, g In the training mode, the optimum amplitude correlation parameters are probed dp exclude the influence of the strongly interfering factors of the structure (p, uff, dB) and to transformation of the rheological function Е У (b) in the area of performing the rheological transitions of the first and second types on the process of control of absolute rheological form - 5 zheniye (rheological fields making up the tensor of fields 6, y,

The learning cycle is carried out by varying the degree of truncation of the training sample of samples over the aggregate field from the level p, & Gg of each parameter individually and the entire set of A f (ps & G, Gg). allows to increase the accuracy of control of the absolute rheological fields 20 of the strength characteristics and in- (0j, t, i,) with a significant intensity of immersion of the latter by

level 6, &, J3, while performing electromagnetic sensing of the test object on selected

specimens (samples of the average analysis frequencies in the range of 20 Hz - of the group), which affect the shape

and the system of Schauder functions and in the range of 1 2 EZ

variations in the strength characteristics of controlled products. Then, a truncated training choice of samples is used in the Kelvin and Maxwell regions and the response of the electrodynamic transducer is recorded, and the nature of the amplitudes change (at fixed analysis frequencies) depending on the level of accumulated residual stresses causing the transformation of the rheological function 4 ((e) the resulting amplitude of the probe field when calculating the secondary (refined) estimates of a, (y, S in pe22

33

zone vj ,. 100 ka / m Initially, on the standards of the first group, the harmonic composition of the electrodynamic converter is measured 30 and the multi-parameter estimates of the monitored parameters P t are clearly established using a multiple regression analysis procedure,

In the future, use a truncated representative sample of witness samples (extreme strength

The measurement benchmark is set according to the 40 groups and the average strength group)

AP c) T7G,

where the coefficients Cd and s are set in the training cycle (in its final phase) on a representative sample of witness samples according to the criterion of minimum error variance.

According to the method, as the electrodynamic transducer, a primary transducer is used, which is connected in a differential circuit, affecting the latter with rheological fields from the Hooke area up to their destruction (e, 6,,}, analyze the response of the e-d electrodynamic transducer (spectral composition it) and set the change of the amplitude correction from 6, b, p and residual stresses E, i.e.

  f (fff, V P. br) Multiparameter estimates of the strength characteristics of the test object 6.6, p are set in the first magnetization mode. 1parameter estimates

.. 22) b.

,, .. J3 explicitly defines the inclusion (with the support part), they are confined to a limited training session, holding two orthogonal sampling samples (medium strength group) in the deformation region (Hooke region) of the controlled items.

Regulated measuring windings are relatively magnetizing, and as informative components

electrodynamic transducers use Walsh spectral components recorded at local analysis intervals. In the training mode, optimal parameters are established for the correlation of the sounding amplitude dp to eliminate the influence of strongly interfering factors of structure variation (p, uff, db) and transformation of the rheological function Е У У (b) in the area of making phase rheological transitions of the first and second types to the process of control of absolute rheological zones, Vj, zone. 100 ka / m Initially, on the standards of the first group, the harmonic composition of the electrodynamic transducer is measured and the multi-parameter estimates of the monitored parameters P t in a clear form are established using the multiple regression analysis procedure,

In the future, use a truncated representative sample of witness samples (extreme strength

groups and average strength group)

and affect the latter with rheological fields from the Hooke area until their destruction (e, 6,,}, analyze the response of the e-h electrodynamic transducer (its spectral composition) and determine the amplitude correction change from 6, b, p and residual life, that is

  f (fff, V P. br) Multi-parameter estimates of the strength characteristics of the test object 6.6, p are set in the first magnetization mode. 1parameter estimates

.. 22) b.

,, .. J3 is explicitly defined on a limited tutorial.

are on limited tutorial

Sampling (medium strength group) in the deformation region (Hooke area) of controlled products.

In the measurement mode, in the first mode of magnetization, the strength characteristics of 1 A are clearly established

the characteristics p, e, b, on the basis of the latter, establish the level of sounding in the second mode on the compression (primary amplitude correction), equal to A. (1 - K); and determine the initial estimates of the control parameters

ff,

f

 22

Soglas-Sh

but the latter, as well as the previously established o. ff

the amplitude correlation of the probe amplitude A (1 - / (s) 2 + (s) and determine the secondary, refined

, 1 and b

p perform wto

ratings

The selection of the appropriate probing frequencies according to the proposed method is carried out with the outcome of the ratio for the generalized parameter, which determines the informative zone for capturing information about the properties of the object being monitored by Depth. The choice of frequency grid, eddy current sounding of the control object from their minimum condition with sufficient, complete display of the properties of the control object (a set of physical and mechanical characteristics) is based on orthogonalization of the contribution at each analysis frequency to the controlled scoop of physical and mechanical characteristics

The device works as follows.

The training cycle is initially carried out on a representative sample of controlled items. At the same time, the amplitude of the back-up current is gradually changed in time. in accordance with the program, my mini-computer 27 is in the range of amplitudes no Up. 100 ka / m As informative components, JToT Walsh harmonics recorded at local intervals of the analysis of different signal envelope multiplicities, obtained by changing for each value of the exciting current, normalized by its instantaneous values (at the time moments of it CT + T / 2 p, where K 1, 2, 3 .. ..; n - 0,1,2,3,4,

In order to implement control of the probe action, the control object of the mini-computer 27 acts on the controller 21 of the magnetizing current through the selector 6, and then the controller 21 magnetizes the current numerically

j

five

0

Q

0

five

0

five

values of the magnetizing current, thereby controlling the shape of the magnetizing current and the frequency of the probe action. The implementation in this form of magnetizing current controller 21 provides the flexibility to vary the sounding frequency when the shape of the probe effect remains constant in the frequency range. This allows us to simplify the implementation of the probe control path and, in addition, independently regulates the parameters of the probe action according to the magnetization form and its frequency,

In this case, the magnetizing current controller 21 through the multiplexer 22. Registers 23 and 24 affect the controlled oscillator 25 and the driver 26. The magnetizing current. In the learning mode, the magnetizing current controller 21, based on the specified step (using the mini-computer 27) of the iterative search procedure, forms the probing effect in an explicit form by the criterion of the minimum error variance.

In the first training mode, the type of regression equations that form O:; Eki of the monitored strength characteristics of e, c, p is established by coefficient weighting. neither informative components)., ft of this electromotive, agnitnyy converter 2 is entered into an absolute mode; measurements using an analog switch 8, the latter being controlled by the mini-computer 27 via the interface node 11, the selector 6 and the switch control block 7, m. The minicomputer 27 sets the polling pattern (single, its address part, sequential polling, polling intervals, etc.), based on which the switch control unit 7 generates a sequence of switches of the analog switch 8 in time with reference to the magnetizing current.

To change the volumetric stress state, the electromagnetic transducers 2 and 3 contain orthogonally located secondary windings, which are made in the form of two separate sections spaced by 3-5 lengths of the sections indicated. In this case, using an analog switch 8, which is synchronized by block 7 of the

7

The switch operates alternately (synchronously) switching the indicated sections of the measuring (secondary) windings,

In the first phase of the second training cycle, informative probing frequencies are set when the voltages in the monitored object vary. At the same time, the mini-computer 27 sets the initial sounding frequency, the shape and amplitude of the signal. The received signal from the electromagnetic transducers is read in the block 10 of the buffer memory, and then in the mini-computer, where it is processed. By setting the corresponding samples, the device is trained according to the relevant criteria. The learning cycle is completed after the order of the change in the amplitude of the acting signal on the test object is established.

The device in the measurement mode operates as follows.

Initially, the impact of the control object (using the probe control path) stepwise in amplitude (triangular form) by the probe field at a fixed frequency, for example, 40 Hz in the amplitude range up to V. 100 KA / M and register

A CLIC, information about which through the path of collecting and processing measurement information enters the mini-computer 27. In the latter, the spectral harmonic composition is initially calculated according to the established algorithms. walsh basis on local analysis intervals, and then estimates

Parameters 6, b, p-Mini-computer 27 acts initially on the selector 6 and on the magnetizing current controller 21, affecting the controlled generator 25 and the magnetizing current driver 26, through multiplexer 22 and registers 23 and 24 ensuring the formation of step-wise amplitude (triangular shape) probing effect on the object of control with the help of a block

magnetization. After calculating the paA parameters b, b, p controlled

minicomputer products 27 translates work

That device in the second measurement mode is 55 quality controlled product.

neither In this case, using an analog switch 8, electromagnetic transducers 2 and 3 are connected according to a differential circuit.

f5

20 -25 DA

88579 8

In this mode, measurements are carried out by multi-frequency (alternately switched) sounding of the test object in the range of 20 Hz - 50 kHz. Initially, the test object is alternately affected at each analysis frequency (f, ..., .., f) by the influence of

FTJ

optimal shape with initial amplitudes A, j, with those established in the first phase of the second training cycle. With this mini-computer. 27, having an effect on the magnetizing current controller 21, provides an initial correction of the amplitude of sounding based on the established (calculated) estimates

1, e.

6, .- ё, 6j (as described).

 . -

(Hereinafter, the acquisition and processing path of the measurement information calculates the primary estimates 6,, 622 of which (ff

, b ,, on the basis of

  l; Y „„ .2 33 I gb

p) perform a secondary correction of the amplitude of sounding by the controller 21 magnetizing current, which ensures the output of the form of the magnetizing current to the magnetization unit 1 of the corrected amplitude of sounding (secondary correction), based on which the τ 6 computer calculates the secondary estimates of 6 6 ё, the secondary estimates), the secondary estimates of Δt are calculated by the miniature computer. In this process

11 2, 33,

The measurement of the physico-technical parameters of ferromagnetic products is completed.

F o rmula of the invention

1, A method of multi-paramagnetic electromagnetic control of ferromagnetic products, which consists in successively affecting the controlled product with an electromagnetic field of varying intensity, receives the signal envelope, extracts the spectral components of the received signal by measuring for each value of the exciting current normalized by its instantaneous amplitude values of the information signal at successive times, convert it using Walsh functions and according to the results of the gender analysis the signal is determined

comparing the results of measurements with the results obtained on the reference samples in the learning process, which differs in topics.

9:

that, in order to increase the accuracy of control of the parameters of the products, during the first mode of the magnetize Ieani, in the training cycle, they determine the form of a rough assessment of the strength characteristics, which is influenced by the electromagnetic control object varying according to the Szunki system, iy Schauder, together with a change in the frequency of sounding, the amplitude of which is determined by the condition of the amplitude of the higher Walsh harmonics in the spectrum of the measured signal, the correction; 1d amplitude of scH ry Spii-ora.erG signal with coefficient К „and in the area of elastic deformation with a coefficient K ε st: - Blamp

kitudu proberszogo zozdg ;; - Noah A ,, ,, mechanical evaluation: a set by registering normal components ILI55 weighting factors g. ,, ,, .-, с, с (i 1,2.3) ustavlivot in the training cycle according to the criterion the minimum dispersion of an opercade with a stump of truncation of a training sample, the effects b. and 1; (i; „3) cycle into a cycle ;;;: training in the measurement benchmark of the re 6 of the strength characteristics of Re 6; on the basis of which it carried out the primary correction of amp. and tsi zo P3 skinny impact: and,,,,,,,,,,,,,,,,,,,,,,, projection of ampoules according krterik L., (1 -. (n

which determine the refined secondary estimates of the monitored parameters where.

5ДИ

On

, i.% V ,, (a. Jiu.-)

 (Sr.-

V

k „.Ь

: (:%.

r

h

b.

,

 h e -. - t

- b

f yy - ni N a (,..

S., .6

Bs

EVALUATION of the strength characteristics: hardness, yield strength and tensile strength; respectively, hardness, tensile strength and current limit

0

O

S,, 0,

i

at

the honor of the reference product;

normal stresses in appropriate orthogonal directions;

the value of the level of the limiting transition to the region of the phase rheological transition.

2. A multiparameter control device for ferromagnetic products, containing a magnetizing current generator connected in series, a magnetization unit and an electromagnetic converter, and an analog-to-digital converter, characterized in that, in order to increase the accuracy of control of the parameters of the items, it is supplied sequentially; connected by a magnetizing current controller, a multiplexer, two registers and a controlled generator connected to the magnetizing current generator, a second electric;, magnetic converter connected in series by a selector connected to the magnetizing current controller, a switch control unit and analog cog-mutator, whose inputs are connected to the first and BTOpbiNi electromagnetic converters, and the output is connected to 35 analog-to-digital converter,. two strain gauge transducers connected to an analog switch S connected in series by a stand controller connected to a selector and an actuator, a minicomputer, a block of buffer memory and an interface node, made in the form of serially connected address decoder with 45 memories, connected to the selector of the handshake control unit, the transceiver unit to the inputs of which the selector and the analog-to-digital converter are connected through the 50th block of the buffer memory, the input and output O registers, Conn, chennyh to minicomputers and control registers connected in series, connected .k minicomputers and bus rovatel the formation 55, whose output is connected to selektorus

Editor O. Bugir

Compiled by Yu.Glazkov

Tehred L.Oleynik Proofreader A.Obruchar

Order 7800/41 Circulation 776 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, Projecto st., 4

Claims (2)

Claim 1. The method of multi-parameter electromagnetic control of ferromagnetic products, which consists in sequentially acting on the controlled product with an electromagnetic field of varying intensity, obtaining an envelope of the signal, isolating the spectral components of the received signal by measuring for each value of the exciting current, the instantaneous values of the information signal normalized by its amplitude to serial moments of time, transform it using the Walsh functions and according to the analysis results of this signal determine the quality of the controlled product, _N comparing the measurement results with the results obtained on the reference samples in the learning process, characterized in 7 12.88579 that, in order to improve the accuracy of monitoring the parameters of products, 'in the first magnetization mode in the training cycle, the form of regression equations is determined that form estimates of strength 5 characteristics, a second magnetization cycle is introduced, during which they act on the control object with an electromagnetic zero that varies according to the system of functions Schauder, together with the change in the sounding frequency, the amplitude of which is established from the condition that the amplitude of the higher Walsh harmonics in the measured spectrum is constant. 'of the signal, the amplitude of 15 probes of the probing signal with a coefficient of K „is corrected, and in the region of elastic-plastic · deformation of the deformation with the coefficient of K. _R ? Ustyan-zvlizayt amplitude of the “sounding impact” equal to А _>> estimates of mechanical loads are established by regiotation of the brackets of normal stress components, “weighting factors ε. ·. . B) _a 1. · _s c ^, c _R (1 ~ 1.2.3) are set in the training cycle according to the criterion of minimum dispersion, in terms of the degree of truncation of the training sample, the coefficients b. and 1; - 1 „2, 3) v install in the cycle and in re.20 honor of the reference product; c, c, S'jj — normal stresses ^<1 in the corresponding orthogonal directions; <3 — values of the level of the limiting transition to the region of the phase rheological transition. 2. A device for multi-parameter control of ferromagnetic products, comprising a magnetization current former connected in series, a magnetization unit and an electromagnetic converter, and an analog-to-digital converter, characterized in that, in order to increase the accuracy of parameter control from ~ divisions, it is equipped with a magnetizing current controller connected in series , a multiplexer, two registers and a controlled generator connected to a magnetizing current driver, a second electromagnetic pre An indexer connected in series with a selector connected to the magnetizing current controller, the pressure bench control unit determines the strength characteristics estimates: p, e, S,, on the basis of which, the primary correction of the amplitude of the probing effect is carried out, determining the primary estimates ν · the secondary amplitude correction according to the criterion A ... (1 ~ v 'C „) ^r ' -r (k. _Rr c *) ⁸ , by which the specified secondary estimates of the controlled parameters are determined, where", k =, / ( _a , -I) ⁴ + ( _a - &) 4 (a '; - ' ⁴ 1 P · 2.> - (5 C-uy-yua) '· (i-W ·> * b-. ₍ "P ₅ I AA r, b u, £ - estimates of strength characteristics: hardness, yield strength and switch and an analog switch, the inputs of which are connected to the first and second electromagnetic converters, and the output is connected to 35 analog-to-digital converter,. two strain gauge transducers connected to an analog switch, connected in series with a stand controller connected to a selector, and an actuator, minicomputers, a buffer memory unit and an interface unit made in the form of 45 address memory decryptors connected in series to a control unit selector by acknowledging a transceiver unit to the inputs of which a selector and an analog-to-digital converter are connected via a 50 block buffer memory, input and output. registers connected to the minicomputer, and connected after the next tensile strength: p, S, e _a ~, respectively, the TE FC shielding strength, tensile strength, and current limit of the control register connected to the minicomputer, and bus driver 55, the output of which is connected to the selector.